Gordon Brown will raise taxes on gas-guzzling cars this week in a 'prime ministerial' Budget designed to promote his vision for the country for the next decade.

The Chancellor will increase the cost of the tax disc for vehicles that pollute most and cut it for cleaner, greener cars. This will be one of a series of announcements aimed at 'drawing clear dividing lines' between Brown's vision for the future and that of the new Conservative leader, David Cameron.

With Cameron making a high-profile push to establish new environmental credentials for the Tories, Brown's plan to make car tax greener won a welcome yesterday from environmental groups. 'The Chancellor is talking more about environmental issues - a good thing,' said Simon Bullock, of Friends of the Earth. 'We would like to see him bring the tax disc for the least-polluting cars down to zero.'

Among other expected measures in Brown's tenth Budget speech as Chancellor, to be delivered on Wednesday, is a support package for training women to enter traditionally male professions such as plumbing and construction, as well as an expansion of the children's trust fund to include further payments as a child grows up, probably at seven and 11.

The training boost for women is in line with recommendations by the government's Women in Work Commission, which found that women often get trapped in the 'five c's' - cleaning, catering, caring, cashiering and clerical work. Brown will present it as one way of preparing Britain to compete with fast-growing economies like China and India.

The Budget announcements, sources close to the Chancellor said yesterday, were part of an effort to contrast his economic experience and vision with what they termed Cameron's inexperience and 'laissez-faire reliance on charities and voluntary groups'.

The Chancellor will also use the Budget to counter suggestions that a Brown premiership would signal a return to old-Labour policies of tax and spend. 'Public finances are tight,' explained one Treasury source yesterday. A government minister added: 'The real battles will come next year, when Gordon is putting the finishing touches on his comprehensive spending review' This is widely seen as a programme for government after Tony Blair has gone. He added that 'except for health and education, all the big departments are looking with fear towards the review'.

Cameron is expected to accuse the Chancellor of jeopardising Britain's competitiveness by increasing taxes. The shadow chancellor, George Osborne, said: 'Our ability to compete in the global economy is being steadily eroded,' adding that he expected this week's statement to be a 'Budget for Brown, not a Budget for Britain'.